I know this has been discussed before, but I've been experimenting with a pvp deck with 15 avalon islands in it and so far only lost 1 match vs an equally gimmicky deck specifically made to counter it.

I'm not saying the deck is unbeatable in general (it has its weaknesses and a few matches could have gone either way), but any player that doesn't have one of the few counters will effectively not be able to do anything for the duration of the entire match.

With the limited card base I was never that much in favor of limitations, but this may be something to look into.